Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The DNA methylated by Hha I methylase was resistant against cleavage of Hae II or Aha II endonuclease indicating that the methyl group of the C5 position of the inmost cytosine nucleotide interferes with the interaction between the enzyme and the hexameric recognition sequence. Considering that Hae II or Aha II methylase has not been isolated yet, the result explained above is a useful information for protecting a double stranded DNA from being cleaved by Hae II or Aha II endonuclease. In contrast to Hae II or Aha II endonuclease, Ban I endonuclease which also has Hha I sequence as its tetrameric core was able to cleave the same DNA normally. This result suggests that the C5 position of the inmost pyrimidine nucleotide is not an important contact point between Ban I endonuclease and its hexameric recognition sequence.
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PMID:The effects of DNA methylation by Hha I methylase on the cleavage reactions by Hae II, Aha II and Ban I endonucleases. 303 32

Members of the MutL family contain a novel nucleotide binding motif near their amino terminus, and the Escherichia coli protein has been found to be a weak ATPase (Ban, C., and Yang, W. (1998) Cell 95, 541-552). Genetic analysis has indicated that substitution of Lys for Glu-32 within this motif of bacterial MutL results in a strong dominant negative phenotype (Aronshtam, A., and Marinus, M. G. (1996) Nucleic Acids Res. 24, 2498-2504). By in vitro comparison of MutL-E32K with the wild type protein, we show the mutant protein to be defective in DNA-activated ATP hydrolysis, as well as MutS- and MutL-dependent activation of the MutH d(GATC) endonuclease and the mismatch repair excision system. MutL-E32K also acts in dominant negative manner in the presence of wild type MutL in vitro, inhibiting the overall mismatch repair reaction, as well as MutH activation. As judged by protein affinity chromatography, MutL and MutL-E32K both support formation of ternary complexes that also contain MutS and MutH or MutS and DNA helicase II. These findings imply that the MutL nucleotide binding center is required for mismatch repair and suggest that the dominant negative behavior of the MutL-E32K mutation is due to the formation of dead-end complexes in which the MutL-E32K protein is unable to transduce a signal from MutS that otherwise results in mismatch-dependent activation of the MutH d(GATC) endonuclease or the unwinding activity of helicase II.
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PMID:The MutL ATPase is required for mismatch repair. 1073 42

Sau3AI is a type II endonuclease that cleaves GATC sequences, producing sticky ends with 4-nucleotide 5'-overhangs. Its activity is inhibited by cytosine C5-methylation within the target sequence. In the N-terminus, Sau3AI exhibits sequence similarity to the GATC-specific single-strand nicking endonuclease MutH implicated in mismatch repair (Ban and Yang, 1998). Sequence analysis of Sau3AI and its homologs reveals that Sau3AI possesses an additional MutH-like domain in the C-terminus. Structure prediction suggests that the C-terminal domain lacks the endonuclease active site but retains all putative DNA-binding elements. As an illustration of these findings, a model of quaternary structure of Sau3AI complexed with the target DNA is presented. These predictions have implications for evolution, structure and function of bacterial DNA repair enzymes and restriction endonucleases.
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PMID:A model of structure and action of Sau3AI restriction endonuclease that comprises two MutH-like endonuclease domains within a single polypeptide. 1193 Sep 90

The development and standardisation of a novel, highly sensitive and specific one-step hot start multiplex RT-PCR assay is presented for the simultaneous and differential diagnosis of African swine fever (ASF) and Classical swine fever (CSF). The method uses two primer sets, each one specific for the corresponding virus, amplifying DNA fragments different in length, allowing a gel-based differential detection of the PCR products. Universal detection of ASF and CSF virus strains was achieved through selection of primers in conserved viral genome regions. The detection range was confirmed by analysis of a large collection of isolates of the two viruses. The high specificity of the assay was proven by testing related viruses, uninfected cell line cultures and healthy pig tissues. Additional confirmatory tests of the ASF and CSF virus amplicon specificity, based on restriction endonuclease analysis with BsmA I or Ban II, respectively, are also described. The analysis of whole blood and serum samples from experimentally infected animals proved the usefulness of the method for an early diagnosis of both diseases, even before the appearance of the first clinical signs. A study of 150 positive field samples from several ASF and CSF outbreaks showed the suitability of this method for a rapid (less than five hours), sensitive and specific differential diagnosis in clinical samples. In addition, a highly sensitive and specific uniplex RT-PCR for CSFV was also developed and standardised as a powerful tool for fast and early diagnosis of the disease.
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PMID:A highly sensitive and specific gel-based multiplex RT-PCR assay for the simultaneous and differential diagnosis of African swine fever and Classical swine fever in clinical samples. 1536 58

A high-performance multi-analysis system for genotypic mutation by means of restriction fragment length polymorphisms (RFLP) involving endonuclease treatment of PCR-amplified DNA on a microchip and subsequent analysis by microchip electrophoresis for DNA sizing was developed. A Hitachi SV1210 system, with which 12 samples can be analyzed on a plastic chip with good accuracy as to DNA sizing between 25 and 300 bp, was employed for RFLP analysis. We performed RFLP analysis of the ABO genotypes of blood donors for whom the ABO type was known. Six blood samples were analyzed by PCR to amplify two different regions of the genomic DNA, each of the amplified DNAs containing a different nucleotide polymorphism. To analyze the genes at polymorphic sites 261 and 526, restriction endonucleases Kpn I and Ban I were employed, respectively. When an amplified DNA was digested with each endonuclease on a microchip for 20 min, sequential analysis revealed the presence or absence of the respective restriction site. This analysis was performed within 7 min using a 1/10 volume of a DNA sample in comparison with the conventional method, and the estimated DNA size differed from the predicted size by less than 10 bp. The results indicate the potential of microchip electrophoresis for RFLP with on-chip direct endonuclease digestion and sequential analysis, offering high resolution in a short time.
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PMID:Direct endonuclease digestion and multi-analysis of restriction fragment length polymorphisms by microchip electrophoresis. 1961 12

Restriction enzymes have previously shown the ability to cleave DNA substrates with mismatched base(s) in recognition sequences; in this study, Ban I endonuclease demonstrated this same ability. Single base substitutions were introduced, and fragments containing various types of unpaired base(s) (heteroduplex fragments) within the Ban I endonuclease recognition sequence, 5'-G|GPyPuCC-3', were generated. Each of the heteroduplex fragments was treated with Ban I endonuclease and analyzed by denaturing gradient gel electrophoresis. Our results showed that heteroduplex fragments containing mismatched bases at either the first or third position of the Ban I recognition sequence or, because of the symmetrical structure of the sequence, the sixth or fourth position on the opposite strand were cleaved by the enzyme. Furthermore, these cleaved fragments contained at least one strand corresponding to the original Ban I recognition sequence. Fragments with mismatches formed by an A (noncanonical, nc) opposite a purine (canonical, ca) or a T (nc) opposite a pyrimidine (ca) were cleaved more efficiently than other types of mismatched bases. These results may help elucidate the mechanisms by which DNA and protein interact during the process of DNA cleavage by Ban I endonuclease.
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PMID:Sequence-dependent cleavage of mismatched DNA by Ban I restriction endonuclease. 2847 Aug 91